Children at play, roughhousing dogs, cicadas calling; crowds assembling for the Barca game, traffic beyond that. The distant noises melded with the heat in a thick, dull soup. Tomàs Rey sat beneath a giant cedar in the gardens of the Palau de Padralbes and basked. A mild daze was what hot September afternoons were for, especially in the days before a new job started. If only he had a few beers with him.

His daze was not purely physical. Growing up here, he was used to the flat, hot sunshine, and his jetlag from the return flight had faded a few days back. It was what his travels had revealed. There was a world beyond his knowledge, beyond what six years in the Mossos d'Esquadra could teach. A world of anomalia.

Of course he had said yes to their offer. It felt like something he had been waiting for without knowing it. This was what the world had planned for him, the purpose of his police training. He had known that his life would have more than just shutting down the local mobs and tracking terror suspects. Of course he had aced the Foundation's tests.

A chittering bark interrupted Tomàs' reverie. Two red squirrels spiralled up a nearby pine, pausing to snap and chatter at each other before racing around to opposite sides of the trunk. There were many squirrels in the park, of course. He had seen people feeding them – an elderly lady, a man in a wheelchair, a kid of about nineteen, a tourist family. Tomàs was only half-watching, but something about this squabbling pair drew his attention. Did they seem more aggressive than usual? Was the smaller squirrel scratching at the bark between sprints?

He had always been observant, but now everything Tomàs saw was alive with unlikely possibilities. The Foundation had told him only one task remained before he could start officially. Exposure to a series of anomalies over several weeks, to gauge his reactions in field conditions. Monitored by the Foundation, but he would not know when or where. Only that it must happen, and that anything could be relevant.

The squirrels raced along a branch, leaping to the next tree and away. On a whim, Tomàs rose and followed them, ignoring the pushchairs and joggers on the paths, eyes searching the canopy above. When he realised he'd lost them, he found himself in deeper shade, a quiet corner of the gardens. There, beneath an azalea bush, he saw the body.

It was another red squirrel. Lying on its back, its belly was split open with a crosswise slice, organs pulled out and draped around the body. Leaning closer, Tomàs could see that its paws had been staked to the ground with rusted nails. The squirrel's head had been flayed and stripped of flesh, but its amputated tail, incongruously bright and fluffy, was looped through the eye-holes of its skull. What the shit? This had been deliberate. Ritual.

"She's the seventh this month."

Tomàs spun. There was no sign of the speaker. Had the voice been in his head? He stood up, scanning the surrounding trees.

"Slowly, Agent Rey," came the voice again. "I seek your assistance."

There, obscured by the trees. A human figure, a red and white hood obscuring its face.

"How do you know my name?" said Tomàs, walking forward cautiously. His right hand moved absently to his belt for a police weapon that was no longer there. He pulled out his phone instead.

The figure remained still. "I know many things, Tomàs Rey. Who you are, who you will soon work for, their purpose. I have followers who cooperate with your Foundation, assisting them with containment of a particular anomaly. Now I would ask the Foundation's help in return."

Tomàs recalled his training, holding down a button on his phone to send an image to the Foundation database for automated cross-checking. Now to keep this anomaly talking.

"Why do you want my help?" He was getting slowly closer, but figure was still turned away from him.

"Because there are things that even I do not know, Tomàs Rey. Someone in Barcelona is murdering my charges. You have been a detective. You must help me find who is behind this."

"Your charges? You mean the squirrels?"

The figure turned. Though it had the body of a man, beneath the hood was red fur, pricked ears, long incisors and eyes shining black.

It spoke again in his mind. "Yes. The tree-folk are my people, and they worship me."

Tomàs glanced at his phone. Possible match: SCP-3761-2. Euclid, Reality-Bender, Uncontained, Non-hostile. Associations: Sciuridae. Okay, he thought, rules of engagement for reality benders. Do not antagonise, look for containment options, minimise public exposure. He would show the Foundation he could ace this test as well.

He spread his hands low and wide. "The tree-folk, right? Well I'm sure the Foundation can assist you, but you probably know I'm not a full agent yet. Perhaps we could go to our Barcelona facility, and you could make a formal request?"

The squirrel-head cocked to the side, as if in rebuke. "You will not contain me, Tomàs Rey, and there is no time to waste on an attempt. I have neglected the prayers of my people for too long. They are thoughtless, and vain, and sometimes cruel, but they depend on me. I will not forsake them this time."

"Okay, perhaps we can do this another way. But will you let me tell my people what I am doing? You must know that I have to follow protocol."

"So how do you enjoy being a god?" he asked, stalling. Inwardly he slapped himself: this was an anomaly, not a girl at the club. He needed to stay focussed, find a new conversational rhythm. But what does one say to a deity?

The figure seemed to sigh. "I did not ask for this calling," it said. "When I was granted my power, I exercised it well, but for many years I have spurned it. It seemed wasted on ungrateful recipients. But I regret my negligence. A parent should love their children, without condition. With your help I will make it right."

Rey's phone buzzed. Negative. SCP-3761 not part of training. Proceed with caution.
Not part of training? Suddenly Tomàs was a lot more interested. He looked again at the solemn figure before him.

"Now do you understand?" it asked wryly. "The Foundation has not chosen me. I have chosen you. Let us waste no more time."

Tomàs did not need further prompting. He strode back to the squirrel carcass, looking at it afresh. The cuts were clean and precise, the mutilation careful and deliberate. This was done by skilled hands.

He turned to the figure. "A human did this. Someone who knew what they were doing."

"Yes. And only to females. They were sending a message." There was anger in the voice.

"No, I don't think so. The body was left here, right? Not on display, not even to the other squirrels. I think this was done for - for supernatural reasons." Rey tried to recall his crash course in thaumaturgy.

"You may be right," said the figure. "Perhaps this is a design, a way to call upon a power. But what power would answer this obscenity? What person would want its attendance?"

"If we knew that, we might know how to find them." Tomàs turned around as if looking for the answer. "I don't know why you're asking me, anyway. For shit do I know about gods and magic."

"And my knowledge stops at the boundary of the human mind. Your kind are foreign to me, so I need you to explain their mysteries. Why would a human do this?"

Tomàs stopped dead, snapping his head towards the figure. "No – not why. How would a human do this? How would they catch a squirrel in the first place?"

"There are only the ritual wounds," said the figure, realisation dawning. "That is the same for all of the victims."

"So they weren't hunted or snared. No defensive wounds either?"

"None."

"And yet the blood from the incisions suggests that it was alive when this was done. Which leaves one likely explanation – someone has been drugging your squirrels."

"Cowards!" The tone was furious.

Rey's mind was already racing ahead. "To drug them in a public park, they would need to blend in someh… Mother of Whores! The squirrel feeders. It must be."

"But even if that is true, there are so many who come to these parks."

"Oh Tomàs, you lazy shit," Rey spat, then gestured to the figure to explain. "In the mossos, they taught us to look for what does not belong. I saw many people feeding squirrels today, but what nineteen year old boy does that?"

As Rey started scanning beyond their secluded copse, the figure put a hand to its furred temple. "He is still here, Tomàs Rey. The south-east corner."

"Wait here, I will find him." Tomàs was already walking quickly away.

The rest of the gardens were busier now, with crowds of fans strolling to the match. Tomàs' eyes skimmed across the throngs, looking for the young man he had seen earlier. There! Exactly where the squirrel-god had said, still throwing crumbs from a paper bag. Tomàs bore down on him swiftly.

Too swiftly: the kid looked up, and Rey's white polo was obvious against the blue and red Barcelona shirts. The young man realised he was a target, dropped the bag and ran from the park. Tomàs set off in pursuit.

He reached the edge of the gardens, but the kid was nowhere. Too many people on the streets, too much movement. Each second he was further behind, but which direction? His hands clenched in frustration.

From above, he heard a loud chirping. Squirrels, six of them in a row on a giant cypress. They stared down at him, then looked pointedly across the road to the south. Then without waiting for him they scurried to the end of the branch, leaped to a lamppost and were off.

Tomàs pushed forward as fast as he could, barging through milling supporters with his eyes flitting from ground level to tree-height. On the second corner to the East, a squirrel waited among the geraniums on a first-floor balcony. It met his eyes, then sprang to the railing and bounded away down the awnings of a side street. Rey followed; out of the crowds, he broke into a run. At the next corner, another squirrel waited, castigating him with animated chirping. Again, as he reached it, it bolted away.

Deeper into the alleys of Barcelona he ran, following the squirrel relay above. The lanes here were shadowed, tall buildings blocking the afternoon light. Few people were about, and the bodegas clamped their shuttered jaws for the siesta. Sweat pricked at Tomàs' brow. Jeans and leather shoes were the wrong things to run in, and the squirrels were too quick. They chattered at him, scolding his earthbound slowness. He pushed on, breathing steadily but heavily.

Through the outskirts of the gothic quarter, his red-tailed guides were waiting in pairs. Shorter relay legs meant he must be gaining. Winding through the narrow streets, he caught a glimpse of a running figure ahead. The kid was flagging now, his gait shot. Tomàs set his face and sprinted, rounding the corner with four squirrels above him in a frenzy.

The kid had turned into a dead end. The shock of it had done for him; exhaustion had caught up before he could turn around, and he was doubled over in the centre of the alley. Tomàs gave a quick check to make sure there were no other exits, letting his heartrate settle, then walked slowly over.

"Hey, melon head," said Rey, his tone friendly. "Why would you want to make me run like that?"

The kid looked up at him. "Go shit yourself," was what he said, but Tomàs could see the fear beneath his bravado and fatigue.

"What are you doing to the squirrels?"

"Your mother –" The curse was cut off by a sudden, deeper fear, and Rey saw that the kid was looking past him.

He heard the voice in his mind as he turned, and he knew the kid could hear it too. "You will not harm my people again!"

Advancing down the alley, flanked by squirrels, was the creature that was their god. The red and white hood was cast back, and the figure's black eyes bore down on the frightened young man.

"You will repent your crimes." The voice was flint.

In the gaze of those implacable eyes, fear broke the kid. He cowered at the end of the alley, hands scrabbling behind him, futile.

"Please, I didn’t – I didn't hurt them. It wasn't my idea. Please, you have to – " Tears ran unnoticed from his eyes.

The figure stepped past Rey.

"Please, I just gave them the food," stammered the kid. "I would never – oh god, don't, don't hurt me. They made me do it. Just this one thing, they said, and I could have anything. Money, friends, all the pussy I could ever want. Please!"

Tomàs took a step after the figure. "Hold on, we need to –"

The honour-guard of squirrels stopped and turned to him as one. Rey hesitated a second, and then it was too late.

With a final stride, the squirrel-god reached the kid. It placed its hands on his trembling shoulders.
"I have been a loving god," its voice rang, "an absent god, a neglectful god. But my believers have never wavered, and they have cried out for me. And so today, I shall be a vengeful god!"

The figure's hands pressed suddenly together and downwards, and the young man's body crumpled in on itself. Tomàs shouted, and the gathered squirrels chirruped wildly. The figure brought its hands into a ball. There was a small, bright flash. When the hands opened, they held a squirrel. Red, small – a juvenile.

"Go," said the god to its tiny new creation. "Flee. Live, if you can." It threw the juvenile upwards, where it clutched at a drainpipe and scrabbled out of sight.

Full of frustration, Tomàs rounded on the squirrel-god. "Shit on the host, what did you do? We needed him for answers!"

"You wanted him for answers," it replied. "I did not need answers. Only to stop him. And to punish. Now he will see how my people live. He will be lucky to find enough food for a week, if the dogs don’t get him first."

"But you heard him. Others were involved. How can we learn their purpose?"

"That is your concern, Tomàs Rey. They will not attack the tree-folk again. If you wish to know more, your Foundation must uncover it yourselves."

Tomàs realised that the squirrels had gone, sliding away while he had raged at the figure in their centre. The sky above had paled as the afternoon faded towards dusk.

"I am grateful for your help," said the figure. "I will tell my people to watch for you, Tomàs Rey. If you need them, they will be there."

It pulled up the hood over its ears, nodded slowly at him, and walked out of the alley. Tomàs knew that when he rounded the corner, there would be no sign of it.

He was alone in the back streets of the gothic quarter. Somewhere above, a television began to blare the raucous noise of the match. Tomàs stood for a long time, thinking, as the city darkened.

Whoever was behind this, he would find them, and bring them to the Foundation.